Technical Field
The present invention relates to a pest control aerosol
sprayer, i. e., an aerosol sprayer for exterminating a noxious insect,
comprising a pressure-tight container containing therein a noxious
insect behavioral inhibitor and a head cap attached to a top of the
pressure-tight container and provided with a spray nozzle, for
spraying the noxious insect behavioral inhibitor in the pressure-tight
container through the spray nozzle of the head cap to exterminate
the noxious insect.
Background Art
A pest control aerosol sprayer has so far consisted of a her-
metically closed pressure-tight container and a head cap attached to
a top of the pressure-tight container.
The pressure-tight container is provided at a top center the-
reof with a valve including a vertically movable stem, the container
containing an insectifuge therein. The insectifuge contained in the
pressure-tight container is a liquid mixture of an insecticide and a
liquefied petroleum gas (LPG) as its propellant.
Also, the head cap is provided with a spray nozzle directed
forwards and on its rear side with an operating button.
And, in an operation of the pest control aerosol sprayer,
pressing the operating button on the head cap by a user pushes down
the stem of the valve in the pressure-tight container to cause the in-
sectifuge contained in the pressure-tight container to be sprayed un-
der its internal gas pressure via the stem of the valve in the pres-
sure-tight container and forwards through and out of the spray noz-
zle on the head cap.
Such a pest control aerosol sprayer, however, in which the
insectifuge contained in the pressure-tight container has an insecti-
cide mixed therein has had several restrictions. Thus, since the in-
secticide exerts an adverse effect not a little on the human body, its
use in the vicinity of a kitchen where there are foodstuff and table-
ware likely infested with noxious insects gives rise to the problem
that the insecticide in the insectifuge sprayed comes to adhere to
foodstuff and tableware. Or its use in a room where there is a baby
or small infant does the problem that the insecticide comes to be
sprayed on the baby or small infant. Thus, in the vicinity of a
kitchen where there are foodstuffs and tableware or in a room where
there is a baby or small infant it has been the actual fact that the
pest control aerosol sprayer is refrained from using or is not used at
all.
Accordingly, instead of an insectifuge using an insecticide
exerting an adverse effect on the human body, it has become known
in recent years to use a pest control aerosol sprayer using a noxious
insect behavioral inhibitor having a refrigerating effect and little
adversely affecting the human body. To cite an example, as shown in
JP 2004-168948 A a noxious insect behavioral inhibitor containing
dimethyl ether and water is used which is caused to attach to a nox-
ious insect to refrigerate the noxious insect, thereby terminating its
behavior, i. e., to kill it by its paralysis.
Such a pest control aerosol sprayer, however, has the problem
firstly that the pressure-tight container to contain the noxious insect
behavioral inhibitor cannot be made of normal steel but must be
made of aluminum to avoid its rusting, corrosion or the like; an alu-
minum made pressure-tight container is high in price, making the
pest control aerosol sprayer highly expensive. Secondly, the problem
is had that dimethyl ether used in the noxious insect behavioral in-
hibitor has a chemical property that it is exceptionally high in
flammability, giving rise in its storage and use to the problem of a
fire or burn. Other than dimethyl ether, materials which have been
used for the noxious insect behavioral inhibitor have their flamma-
bility as strong as dimethyl ether, much likely to lead to the problem
of a fire or burn.
Also, a pest control aerosol sprayer using an insectifuge hav-
ing mixed therein an insecticide, not a noxious insect behavioral in-
hibitor, is likely to lead to the problem of a fire or burn because of
the use as its propellant of a liquefied petroleum gas that is strong
in flammability.
Accordingly, it is an object of the present invention to provide
a pest control aerosol sprayer for exterminating noxious insects
which is free from bringing about such problems, in particular the
problem of a fire or burn that is its most important matter.
Disclosure of the Invention
The present invention provides in a first aspect thereof a pest
control aerosol sprayer, which comprises: a pressure-tight container
containing therein a noxious insect behavioral inhibitor of which an
active ingredient is an alternative for chlorofluorocarbon acting also
as both a propellant and refrigerant, the pressure-tight container
having at its top a valve provided with a stem and in the stem with
an injection hole that can be opened with the stem forced down; and
a head cap attached to a top of the pressure-tight container and pro-
vided with a spray nozzle and an inflow port in which the stem of the
valve in the pressure-tight container is fitted, the head cap being
formed therein with an injection passage leading from the inflow
port to the spray nozzle.
The present invention provides in a second aspect thereof a
pest control aerosol sprayer according to the first aspect mentioned
above, in which the alternative for chlorofluorocarbon that is an ac-
tive ingredient of the noxious insect behavioral inhibitor is
HFC-152a.
The present invention provides in a third aspect thereof a
pest control aerosol sprayer according to the first aspect mentioned
above, in which the alternative for chlorofluorocarbon that is an ac-
tive ingredient of the noxious insect behavioral inhibitor is
HFO-1234yf.
The present invention provides in a fourth aspect thereof a
pest control aerosol sprayer according to the first aspect mentioned
above, in which the alternative for chlorofluorocarbon that is an ac-
tive ingredient of the noxious insect behavioral inhibitor is
HF01234ze.
The present invention provides in a fifth aspect thereof a pest
control aerosol sprayer according to any one of the first to fourth as-
pects mentioned above, in which the injection passage formed in the
head cap is provided with a pressure reducer means for lowering the
pressure of a gas prior to its reaching the spray nozzle.
The present invention provides in a sixth aspect thereof a
pest control aerosol sprayer according to the fifth aspect mentioned
above, in which the pressure reducer means includes injection pas-
sages bifurcated into and provided with at least two spray nozzles
whereby the pressure of the gas is lowered prior to its reaching a
spray nozzle.
According to the present invention, using a noxious insect
behavioral inhibitor of which an active ingredient is an alternative
for chlorofluorocarbon acting also as both a propellant and refriger-
ant allows refrigerating a noxious insect and terminating the behav-
ior of the noxious insect, i. e., killing the noxious insect on its para-
lyzing, thereby exterminating the noxious insects, without adversely
affecting the human body. And, using as the active ingredient of the
noxious insect behavioral inhibitor, an alternative for chlorofluoro-
carbon which has the chemical property that it is very low in flam-
mability, eliminates the problem such as of a possible fire or burn in
its storage or use, and thus serves to provide extremely safe products
of a pest control aerosol sprayer.
Also, if the noxious insect behavioral inhibitor is used of
which an active ingredient is an alternative for chlorofluorocarbon
such as HFC-152a, HFO-1234yf or HF01234ze whose gas pressure is
extremely high, the pest control aerosol sprayer equipped with a
pressure reducer mean in the injection passage of the head cap al-
lows the pressure reducer means to lower the pressure of gas prior to
its reaching a spray nozzle, thereby rendering the noxious insect be-
havioral inhibitor in the form of a mist whose small drops are of a
desired particle size for shooting successfuly from a spray nozzle.
Brief Description of the accompanying Drawings
In the Drawings:
Fig. 1 is a front view of a pest control aerosol sprayer ac-
cording to the present invention,"
Fig. 2 is a side view of the pest control aerosol sprayer ac-
cording to the present invention!
Fig. 3 is a cross sectional view taken along the line III-III in
Fig. 1; and
Fig. 4 is an enlarged cross sectional view illustrating the
neighborhood of a head cap.
Best Modes for Carrying Out the Invention
Mention is made of a pest control aerosol sprayer as one form
of implementation of the present invention.
The pest control aerosol sprayer as shown in Figs. 1 and 2
consists of a hermetically closed pressure-tight container 1 and a
head cap 2 attached to a top of the pressure-tight container 1.
As shown in Figs. 3 and 4, the pressure-tight container 1 is
provided in an upper and central area thereof with a valve 3 in which
a vertically movable stem 5 having an injection hole 4 is forced up-
wards by a spring 6. The valve 3 is so designed that moving the stem
5 downwards causes the injection hole 4 in the stem 5 to be opened.
The pressure-tight container 1 is made of steel but it does not intend
to be limited to being so.
And, the pressure-tight container 1 contains a noxious insect
behavioral inhibitor A which has an alternative for chlorofluorocar-
bon acting as an active ingredient and also as a propellant and re-
frigerant. The alternatives for chlorofluorocarbon include hydro-
fluorocarbon and hydrofluoroolefin and these alternatives for chlorof-
luorocarbon have a chemical property that their flammability is very
low. And, as the alternative for chlorofluorocarbon in this form of
implementation is used HF0152a (1, 1-difluoroethane) (chemical
formula: CHF2CH3; CAS No. 75-37-6) that is a kind of hydrofluoro-
carbon. The content of HF0152a in the noxious insect behavioral in-
hibitor A will be described later herein. While hydrofluorocarbon for
use may not necessarily be HFC-152a but may be HFC-134a (chemi-
cal formula: CH2FCF3; CAS No. 811-97-2) as another kind thereof, it
should most preferably be HFC-152a, taking into account use condi-
tions, operations and effects. However, there are very suitable ones
other than hydrofluorocarbons such as HFC-152a. For example, they
are as hydrofluoro-olefins, HFO-1234yf (2, 3, 3, 3-tetrafluoropropene)
(chemical formula: CF3CF=CH2; CAS No. 754-12-1) and HFO-1234ze
(1, 3, 3, 3-tetrafluoropropene) (chemical formula: CF3CH=CFHl CAS
No. 1645-83-6). Such HFO-1234yf and HFO-1234ze have a global
warming potential (GWP) lower than that of HFC-152a and also have
a chemical property such that they are lower in flammability than
HFC-152a. Moreover, HFO-1234ze is not flammable at all and thus
nonflammable. From these reasons it is desirable, too, to use
HFO-1234yf and HFO-1234ze as alternatives for chlorofluorocarbon
and especially the latter well, taking into account their chemical
properties.
The head cap 2 is provided with a spray nozzle 10 facing for-
ward and in a lower and central area thereof with an inflow port 11
in which the stem 5 of the valve 3 in the pressure-tight container 1 is
fitted. The head cap 2 is formed with an injection passage 12 ex-
tending to the spray nozzle 10 from the inflow port 11. The head cap
2 is further provided on its rear side with an operating button 13.
Instead of the operating button 13 provided on the rear side
of the head cap 2, there may be provided a trigger lever on the lower
side of the spray nozzle 10 that is a front side of the head cap 2. Also,
instead of facing forwards, the spray nozzle 10 may be made to face
upwards.
And, as shown in Fig. 4 the head cap 2 is equipped in its in-
ternally formed injection passage 12 with a pressure reducer means
for decreasing the pressure of a gas before it reaches the spray noz-
zle 10. In a specific example illustrated as the pressure reducer
means, the injection passage 12 is bifurcated into an upper injection
passage 12a and a lower injection passage 12b and the spray nozzle
10 is mounted to the end of each of the upper and lower injection
passages 12a and 12b. By means of bifurcating the injection passage
12, the pressure of the gas is caused to decrease before it reaches the
spray nozzle 10. For such an injection passage 12, let it be here that
the injection passage 12 prior to bifurcation is of a diameter D of 3 to
4 mm, the upper injection passage 12a is of a diameter Da of 1.5 mm
and the lower injection passage 12b is of a diameter Db of 1.8 mm.
Making the size (diameter Da) of the upper injection passage 12 a
little smaller than the size (diameter Db) of the lower injection pas-
sage 12b in this manner allows rendering conditions of spraying from
the upper and lower spray nozzles 10a and 10b even and sufficient.
Also, while the pressure reducer means provided in the injec-
tion passage 12 bifurcates the injection passage 12, it does not in-
tend to be limited to doing so. The pressure reducer means may bi-
furcate or divide the injection passage 12 into three or more passage
parts provided with three or more spray nozzles 10. Further, instead
of bifurcating the injection passage 12, the injection passage 12 may
be provided midway therein with a pressure reducing or decom-
pressing chamber that is larger in cross section than the injection
passage 12. As the pressure reducer means, however, bifurcating the
injection passage 12 is the simplest and quite plain to facilitate
manufacturing.
And, in operation of the pest control aerosol sprayer shown,
pressing the operating button 13 in the head cap by a user forces
down the stem 5 of the valve 3 to open the injection hole 4 in the
stem 5 whereby the noxious insect behavioral inhibitor A contained
in the pressure-tight container 1 is forced by its propellant action,
namely under gas pressure to flow from the injection hole 4 of the
stem 5 in the pressure-tight container 1 into the inflow port 11 and
the injection passage 12 in the head cap 2, then splitting to flow into
the upper and lower injection passages 12a and 12b which are bifur-
cated into as the pressure reducer means in the injection passage 12.
Flowing through the upper and lower injection passages 12a and 12b,
the noxious insect behavioral inhibitor A is then sprayed forwards
from the upper and lower spray nozzles 10a and 10b. And, if the
noxious insect behavioral inhibitor A getting into the air adheres to
an noxious insect, the insect will in a moment be refrigerated and
terminated of its behavior, i. e., be paralyzed and killed, thus exter-
minated.
It is noted here that a noxious insect behavioral inhibitor A
having an alternative for chlorofluorocarbon acting as an active in-
gredient and also as a propellant and refrigerant, specifically a nox-
ious insect behavioral inhibitor A having HFO 152a acting as an ac-
tive ingredient is considerably high in gas pressure, having a gas
pressure as high as 4 to 5 kgf/cm3 or more (at 25°C), compared with
liquid petroleum gas (LPG) usually used as propellant, which has a
gas pressure of 2.8 kgf/cm3 (at 25°C). Another alternative for chlo-
rofluorocarbon has a high gas pressure as well as this. Consequently,
spraying the noxious insect behavioral inhibitor A in an ordinary
manner causes the noxious insect behavioral inhibitor A to be too
high in gas pressure at the spray nozzle 10 and to be sprayed in the
form of a mist of exceedingly small drops or particles, which renders
the efficiency of adherence of the noxious insect behavioral inhibitor
to noxious insects low and fails to achieve satisfactory behavioral in-
hibiting effect. Accordingly, in the present invention there is pro-
vided a pressure reducer means as a pressure dividing mechanism
that bifurcates the injection passage 12 formed in the head cap 2,
thereby enabling the pressure of the gas when sprayed from the
spray nozzle 10 to be lowered to some degree. This allows the noxious
insect behavioral inhibitor A when sprayed through the spraying
nozzle 10 to be sprayed in the form of coarse mist particles, thereby
increasing the efficiency of its adherence to noxious insects and en-
hancing their refrigerating effect, thus achieving the satisfactory
behavioral inhibiting effect. And, the noxious insect behavioral in-
hibitor A when sprayed has an average particle size of 60 to 200|J m,
preferably 70 to 150|J m. In comparison, an insectifuge having an or-
dinary insecticide mixed therein in a conventional pest control aero-
sol sprayer has an average particle size of around 20\i m. And, with
the average particle size less than 60|J m, the particles come to soar
and scatter along surfaces of noxious insects, and adherence of the
noxious insect behavioral inhibitor A to noxious insects is very poor.
Mention is next made of the content of HF0152a in the nox-
ious insect behavioral inhibitor A.
HFOl52a itself acting also as a propellant and refrigerant, it
can be used alone in and as the noxious insect behavioral inhibitor A,
although a separate substance or substances can be mixed therewith.
In this case, HFC-152a is contained at a proportion of 75 % or
more. In other words, the content of HFC-152 is 75 to 100 %.
And, substances that can be mixed in HF0152a are dimethyl
ether, normal butane, isobutan, propane and their mixed gases as
liquefied petroleum gases. But, being flammable, they if mixed much
become high in flammability. Thus, when mixed with them,
HFC-152a must be of a content of no less than 75 %. If HF0152a
having a content of less than 75 % is sprayed at a fire origin or the
like, it is likely to lead to a backfire causing a serious problem such
as of a fire or burn. Also, while hydrocarbon normal pentane,
isopentane, normal hexane or the like having the carbon number of 5
or 6 which is high in boiling point may be mixed, it is high in flam-
mability, requiring its mixing ratio to be set low. Besides, it is possi-
ble to mix a compressed gas such as of nitrogen, air or carbon diox-
ide.
Mention is further made of the content of other than
HF0152a in the noxious insect behavioral inhibitor A. For example,
HFO-1234ze with the aforementioned flammability and likely back-
firing problem taken into account can have its content reduced com-
pared with HF0152a. However, since reducing its content down to
less than 50 % lead again to the problem, the content must be 50 %
or more. In other words, HF01234ze needs to be contained at a pro-
portion of 50 to 100 %.
Further, the noxious insect behavioral inhibitor A may have
an insecticide a little intermixed therewith for the purpose of a le-
thal or repellent effect. Such insecticides may, for example, be pyre-
throid insecticidal components such as methofluthrin (trade name:
Eminence), dl, d - T80 - allethrin (trade name: Pynamin Forte),
phthalthrin (trade name: Neopynamin), d - T80 - phthalthrin (Neo-
pynamine Forte), d, d - T98 - prallethrin (trade name; Etoc), d, d -
T98 prallethrin (trade name: 98 Etoc), d — T80 — resmethrin (trade
name: Chrysron Forte), transfluthrin (trade name: Biothrin), imi-
prothrin (trade name-Pralle), etofenprox (trade name:Torebon), cy-
phenothrin (trade name: Gokilaht), d, d - T - cyphenothrin (trade
name: Gokilaht S), empenthrin (trade name- Paperthrin), permethrin
(trade name: Xmin), phenothrin (trade name: Sumithrin) and pyre-
thrin (trade name: Chrysanthemum Expel), organic phosphoric in-
secticidal component such as fenitrothion (trade name: Sumithion)
and marathion (trade name: Marathon) and carbamate insecticidal
components such as propoxur (trade name:Baygon) and culverin
(trade name: NAC). For natural essential oils can be cited citronella
oil, thyme oil, peppermint oil, lavender oil, coriander oil, cedarwood
oil, fennel oil, chamomile oil, cinnamon oil, pimento oil, geranium oil,
cumin oil, Japanese peppermint oil, clove oil, hiba oil and lemon
grass oil. These components can be used singly or on mixing two or
more of them, depending on their uses. Such an insecticidal liquid
if incorporated should have a content of 0.0001 to 2 weight/volume %
such as not to adversely affect the human body.
Also, as a solvent it is desirable to use 2, 3 - dihydrode-
cafluoropentane (Mitsubishi - Du Pont Fluorochemicals, Co. Ltd.,
trade name: Vertrel XF) or 1, 1 - difluoroethane (Sumitomo 3M, Co.
Ltd., trade name: HFE), which is a nonflammable solvent.
By using such a nonflammable solvent, it is possible to provide a pest
control aerosol sprayer that is extremely low in dangerousness lead-
ing to an explosion or flashing. Further, these solvents have a low
boiling point such as to volatilize at the normal temperature of a
room without remaining and without leaving dirt of such as a mark
of spraying when the sprayer is used indoors. Moreover, being high
in permeability when attached to a noxious insect and also having
themselves a refrigerating effect, a solvent such as 2, 3 - dihydrode-
cafluoropentane or 1, 1 - difluoroethane further enhances the refrig-
erating effect on noxious insects and serves to exterminate noxious
insects yet more effectively.
Also, using a solvent that is high in both attaching perme-
ability and choking effect on noxious insects serves to exterminate
noxious insects still more effectively. For such solvents can be cited,
for example, aliphatic, aromatic and cycloaliphatic hydrocarbons, al-
cohols such as ethanol, isopropyl alcohol and methanol, ester, vege-
table oils, animal oils and water. Among them, an aliphatic hydro-
carbon is excellent in effects in that by refrigerating at the time of
spraying it is solidified and iced, conducing to considerably high
lowtemperature retaining effect. However, being hard to volatilize,
it has the possibility that it leaves dirt of a mark of spraying. The
solvent is therefore set in at a content of not more than 10 % by vo-
lume to get rid of dirt by spray marking.
The pest control aerosol sprayer according to the present in-
vention allows its favorable use indoors because of the property that
it leaves no residue of the noxious insect behavioral inhibitor A in an
sprayed area. Noxious insects that can be effectively targeted
thereby may be cockroaches such as Blattella germanica, Periplaneta
fuliginosa, Periplaneta americana, Periplaneta brunnea Burmeister
and Periplaneta japonica, spiders, centipedes, ants and stinkbugs.
These noxious insects, of course, include also flying insects including
flies such as Musca domenstica, Fannia canicularis, Sarcophagidae,
Aldrichina grahami, Drosophila melanogaster, Psychodidae and
Phoridae, mosquitoes such as Culex pipiens pallens and Aedes al-
bopictus, and flying insects such as bees. The pest control aerosol
sprayer of the present invention also exhibits a control or repelling
effect on pyrethroid resistant noxious insects.
The pest control aerosol sprayer according to the present in-
vention can be used anywhere, i. e., in a variety of places including
not only a general household including a kitchen where there are
foodstuff and tableware and a room where there is a baby or small
infant, but also a restaurant, a hospital and the like, and will not be
restricted by place of use.
Mention is next made of test examples of the present inven-
tion, although the invention does not intend to be limited to them.
Test Example 1 relates to back-fire tests for the aerosol
sprayer using various gases. Specifically, aerosol sprayers loaded
with various gases acting as both propellant and refrigerant were
prepared. And, after these aerosol sprayers were immersed in a
thermostatic bath at 25°C for 1 hour, each of them was arranged
with the flame, as a fire origin, of an ignited burner so that the
spray nozzle of its head cap and the flame lied horizontally in the
same height. And, each gas was sprayed from the spray nozzle of the
head cap in the aerosol sprayer for 5 seconds towards the flame as
the fire origin to check if there was a backfire. This was repeated a
plurality of times. Here, the fire origin was spaced from the spray
nozzle at a distance of 15 cm and at a distance of 60 cm. Results of
the test are shown in Table 1 below.
As the test results, it is shown that with each of LPG, di-
methyl ether, and a mixture of isopentane and LPG, there was a
backfire for both 15cm and 60 cm distant from the fire origin. More-
over, the mixture of isopentane and LPG gave rise to a large flame.
In contrast to these, with each of HF0152a and HFC-134a there was
no backfire for each of 15cm and 60 cm distant from the fire origin. It
is thus seen that HF0152a and HFC-134a as alternatives for
chlorofluorocarbon are extremely low in flammability.
Further, HFO-1234ze as another alternative for chlorofluo-
rocarbon was also subjected to the same backfire tests as for
HFC-152a and HFC-134a in Text Example 1 mentioned above. Re-
suits of the test are shown in Table 2.
In the results of this test, it is shown as in the aforemen-
tioned backfire test that with HFO-1234ze, too, there was no backfire
for each of 15cm and 60 cm distant from the fire origin. It is thus
seen that HFO-1234ze as an alternative for chlorofluorocarbon is
also extremely low in flammability.
In Test Example 2, aerosol sprayers using HFC-152a as an
alternative for chlorofluorocarbon were tested on its content. This,
too, relates to back-fire tests. Specifically, aerosol sprayers loaded
with HFC-152a alone and mixtures of HFC-15a with LPG or dimethyl
ether (in varied mixture ratio) were prepared. And, after these aero-
sol sprayers were immersed in a thermostatic bath at 25°C for 1
hour, each of them was arranged with the flame, as a fire origin, of
an ignited burner so that the spray nozzle of its head cap and the
flame lied horizontally in the same height. And, each gas was
sprayed from the spray nozzle of the head cap in the aerosol sprayer
for 5 seconds towards the flame as the fire origin to check if there
was a backfire. This was repeated a plurality of times. Here, the fire
origin was spaced from the spray nozzle at a distance of 15 cm. Re-
sults of the test are shown in Table 3 below.
As the test results, it is shown that with each of HFC-152a
alone and a mixture of HFC-152a at its mixing ratio of 75 % with
LPG or dimethyl ether, there was no backfire. However, with mix-
tures of HFC-152a at mixing ratios of 50 % and 25 % with LPG or
dimethyl ether, there was a backfire. From these, it is seen that
HFC-152a if its mixing ratio is set at 75 to 100 % in its content is
reduced in flammability to enhance the safety.
Further, HFO-1234ze as another alternative for chlorofluo-
rocarbon was also tested on its content as in Text Example 2 above.
Results of the test are shown in Table 2. Specifically, aerosol spray-
ers loaded with HFO-1234ze alone and mixtures of HFO-1234ze with
LPG or dimethyl ether (in varied mixture ratio) were prepared. And,
after these aerosol sprayers were immersed in a thermostatic bath at
25°C for 1 hour, each of them was arranged with the flame, as a fire
origin, of an ignited burner so that the spray nozzle of its head cap
and the flame lied horizontally in the same height. And, each gas
was sprayed from the spray nozzle of the head cap in the aerosol
sprayer for 5 seconds towards the flame as the fire origin to check if
there was a backfire. This was repeated a plurality of times. Here,
the fire origin was spaced from the spray nozzle at a distance of 15
cm. Results of the test are shown in Table 4 below.
As the test results, it is shown that with each of HFO-1234ze
alone and mixtures of HFO-1234ze at its mixing ratios of 75 % and
50 % with LPG or dimethyl ether, there was no backfire. From this,
it is seen that HFO-1234ze if its mixing ratio is set at 50 to 100 % in
its content is reduced in flammability to enhance the safety. Also,
HFO-1234ze itself being expensive, its mixing with LPG or dimethyl
ether makes it possible to furnish them less expensively. Note fur-
ther that this leaves the flammability low and gives rise to no prob-
lem whatsoever on safety.
In Test Example 3, modes of spraying from the spray nozzle
10 in the head cap 2 were examined. This is to examine the refriger-
ating and behavioral inhibiting effects on a noxious insect by a nox-
ious insect behavioral inhibitor A which is sprayed from the spray
nozzle 10. Specifically, a wooden flooring was prepared on which a
glass ring (having a diameter of 9 cm and a height of 6 cm) was
placed. Then, a rod having a diameter of 3 mm is inserted between
the wooden flooring and the glass ring to form a clearance between
them so that sprayed liquid does not collect inside of the glass ring.
And, one female adult of Periplaneta fuliginosa is introduced inside
of the glass ring. On the other hand, two different head caps were
prepared, one provided with a single spray nozzle 10 and the other
provided with a pressure reducer means comprising an upper and a
lower spray nozzle 10a and 10b. And, using them, the noxious insect
behavioral inhibitor A is sprayed for 3 seconds toward the Pe-
riplaneta fuliginosa from a distance of 50 cm therefrom, and the
state of the Periplaneta fuliginosa thereafter (possible knockdown
after 2 minutes and after 1 hour and fatality after 24 hours) is ob-
served. Further, the minimum temperatures of a target area of
spraying are measured. And, the room temperature is 25°C, and the
noxious insect behavioral inhibitor A is HF0152a alone (100 %). The
two head caps 2, the one with the single spray nozzle 10 and the
other with the two spray nozzles 10, are made to spray substantially
at a identical rate of spraying. Test results are shown in Table 5 be-
low.
The test results indicate that the head cap provided with two
spray nozzles 10, i. e., equipped with a pressure reducer means as a
pressure dividing mechanism that bifurcates the injection passage 12
to reduce the pressure of gas to some degree as it is sprayed from the
cap, makes the sprayed mist coarser and the average mist particle
size larger, and further makes the minimum temperature at the tar-
get area of spraying lower, than with the head cap having a single
spray nozzle. This increases the efficiency of adherence of the nox-
ious insect behavioral inhibitor A on a noxious insect and enhances
the refrigerating effect, thereby achieving satisfactory noxious insect
behavioral inhibiting effects. Note in this connection that with the
head cap with a single spray nozzle alone, gas pressure is excessive,
making mist drops finer and making their adherence on the insect
inferior; as a result, spraying in a short period has failed to achieve
satisfactory noxious insect behavioral inhibiting effects. Moreover,
an excessively energetic spray may have driven the noxious insect to
fly off.
Also, in Test Example 3, noxious insect behavioral inhibitors
containing HFOl234ze alone (100 %), at a content of 75 % and at a
content of 50 % were examined. What is mixed is dimethyl ether.
Test results are shown in Table 6 below.
From these test results it is seen, too, that the head cap pro-
vided with two spray nozzles 10, i. e., equipped with a pressure re-
ducer means as a pressure dividing mechanism that bifurcates the
injection passage 12 to reduce to some degree the pressure of gas as
it is sprayed from the cap, makes the sprayed mist coarser and the
average mist particle size larger, and further makes the minimum
temperature at the target area of spraying lower. This increases the
efficiency of adherence of the noxious insect behavioral inhibitor A
on a noxious insect and enhances the refrigerating effect, thereby
achieving satisfactory noxious insect behavioral inhibiting effects. It
is further seen that ones with HFO-1234ze at 75 % and 50 % achieve
still higher behavioral inhibiting effects.
We Claim:
1. A pest control aerosol sprayer, characterized in that it
comprises:
a pressure-tight container receiving therein a noxious insect
behavioral inhibitor of which an active ingredient is an alternative
for chlorofluorocarbon acting also as both a propellant and refriger-
ant, the pressure-tight container having at its top a valve provided
with a stem and in the stem with an injection hole that can be
opened with the stem forced down; and
a head cap attached to a top of the pressure-tight container
and provided with a spray nozzle and an inflow port in which the
stem of the valve in the pressure-tight container is fitted, the head
cap being formed therein with an injection passage leading from the
inflow port to the spray nozzle.
2. A pest control aerosol sprayer as set forth in claim 1,
characterized in that the alternative for chlorofluorocarbon that is
an active ingredient of the noxious insect behavioral inhibitor is
HFC-152a.
3. A pest control aerosol sprayer as set forth in claim 1,
characterized in that the alternative for chlorofluorocarbon that is
an active ingredient of the noxious insect behavioral inhibitor is
HFO-1234yf.
4. A pest control aerosol sprayer as set forth in claim 1,
characterized in that the alternative for chlorofluorocarbon that is
an active ingredient of the noxious insect behavioral inhibitor is
HFO-1234ze.
5. A pest control aerosol sprayer as set forth in any one of
claims 1 to 4, characterized in that the injection passage formed in
the head cap is provided with a pressure reducer means for lowering
the pressure of a gas prior to its reaching the spray nozzle.
6. A pest control aerosol sprayer as set forth in claim 5,
characterized in that the pressure reducer means includes injection
passages bifurcated into and provided with at least two spray nozzles
whereby the pressure of the gas is lowered prior to its reaching a
said spray nozzle.

A pest control aerosol sprayer is provided that is free from
giving rise to a fire or a burn in its storage or use.
The pest control aerosol sprayer comprises a pressure-tight
container (1) receiving therein a noxious insect behavioral inhibitor
(A) of which an active ingredient is HFC-152a acting also as both a
propellant and refrigerant, the pressure-tight container having at its
top a valve (3) provided with a stem (5) and in the stem (5) with an
injection hole (4) that can be opened with the stem (5) forced down;
and a head cap (2) attached to a top of the pressure-tight container
(l) and provided with a spray nozzle (10) and an inflow port (11) in
which the stem (5) of the valve (3) in the pressure-tight container (l)
is fitted, the head cap (2) being formed therein with an injection
passage (12) leading from the inflow port (11) to the spray nozzle
(10).